Section 26.1 Summary – pages 693-697

1. Section 26.1 Summary – pages 693-697 Sponges are pore-bearers Water out • Sponges are mainly sessile organisms. Central cavity • Because most adult sponges can’t travel in search of food, they get their food by a process called filter feeding. Water in

2. Section 26.2 Summary – pages 698-705 Digestion in cnidarians • Cnidarians are predators that capture or poison their prey using nematocysts. • A nematocyst (nih MA tuh sihst) is a capsule that contains a coiled, threadlike tube. • The tube may be sticky or barbed, and it may contain toxic substances. • Nematocysts are located in stinging cells that are on tentacles.

3. Section 26.2 Summary – pages 698-705 Digestion in cnidarians • Once captured by nematocysts, prey is brought to the mouth by contraction of the tentacles. Mouth Gastrovascular cavity Polyp Mouth Medusa

4. Section 26.2 Summary – pages 698-705 Hydra eating daphnia Digestion in cnidarians • The inner cell layer of cnidarians surrounds a space called a gastrovascular (gas troh VAS kyuh lur) cavity. • Cells adapted for digestion line the gastrovascular cavity and release enzymes over captured prey. Any undigested materials are ejected back out through the mouth.

5. Section 26.4 Summary– pages 711-713 Roundworm parasites of humans • Infection by Ascaris (ASS kuh ris) is the most common roundworm infection in humans. • Children become infected more often than adults do. • Eggs of Ascaris are found in soil and enter a human’s body through the mouth.

6. Section 26.4 Summary– pages 711-713 Roundworm parasites of humans • The eggs hatch in the intestines, move into the bloodstream, and eventually to the lungs, where they are coughed up, swallowed, and begin the cycle again.

7. Section 26.4 Summary– pages 711-713 Roundworm parasites of humans • Pinworms are the most common human roundworm parasites in the United States. • Pinworms are highly contagious because eggs can survive for up to two weeks on surfaces.

8. Section 26.4 Summary– pages 711-713 Roundworm parasites of humans • Its life cycle begins when live eggs are ingested. They mature in the host’s intestinal tract. • Female pinworms exit the host’s anus—usually as the host cell sleeps—and lay eggs on nearby skin. • These eggs fall onto bedding or other surfaces.

9. Section 26.4 Summary– pages 711-713 Roundworm parasites of humans • Trichinella causes a disease called trichinosis (tri keh NOH sis). • This roundworm can be ingested in raw or undercooked pork, pork products, or wild game. Trichinella

10. Section 26.4 Summary– pages 711-713 Roundworm parasites of humans • Hookworm infections are common in humans in warm climates where they walk on contaminated soil in bare feet. • Hookworms cause people to feel weak and tired due to blood loss.

11. Section 26.4 Summary– pages 711-713 Roundworm parasites of other organisms • Nematodes can infect and kill pine trees, cereal crops, and food plants such as potatoes. • They are particularly attracted to plant roots and cause a slow decline of the plant.

12. Section 26.4 Summary– pages 711-713 Roundworm parasites of other organisms • They also can infect fungi and can form symbiotic associations with bacteria. • Nematodes also can be used to control pests.

13. Section 29.1 Summary – pages 763-769 Echinoderms have varied nutrition • All echinoderms have a mouth, stomach, and intestines, but their methods of obtaining food vary. • Sea stars are carnivorous and prey on worms or on mollusks such as clams.

14. Section 29.1 Summary – pages 763-769 Echinoderms have varied nutrition • Most sea urchins are herbivores and graze on algae. • Brittle stars, sea lilies, and sea cucumbers feed on dead and decaying matter that drifts down to the ocean floor.

15. Section 31.1 Summary – pages 817 - 825 How reptiles obtain food • Most turtles and tortoises are too slow to be effective predators, but that doesn’t mean they go hungry. • Most are herbivores, and those that are predators prey on worms and mollusks.

16. Section 31.1 Summary – pages 817 - 825 How reptiles obtain food • Snapping turtles, however, are extremely aggressive, attacking fishes and amphibians, and even pulling ducklings under water.

17. Section 31.1 Summary – pages 817 - 825 How reptiles obtain food • Lizards primarily eat insects. • The Komodo dragon, the largest lizard, is found on several islands in Indonesia, north of Australia. It is an efficient predator, sometimes even of humans.

18. Section 31.1 Summary – pages 817 - 825 How reptiles obtain food • Snakes are also effective predators. • Some, like the rattlesnake, have poison fangs that they use to subdue or kill their prey.

19. Section 31.1 Summary – pages 817 - 825 How reptiles obtain food • A constrictor wraps its body around its prey, tightening its grip each time the prey animal exhales.

20. Section 32.1 Summary – pages 841 – 847 What is a mammal? • Mammals, like birds, are endotherms.

21. Section 32.1 Summary – pages 841 - 847 Most mammals have specialized teeth • Mammals with teeth have different kinds that are adapted to the type of food the animal eats.

22. Section 32.1 Summary – pages 841 - 847 Most mammals have specialized teeth • The pointed incisors of moles grasp and hold small prey. • The chisel-like incisors of beavers are modified for gnawing.

23. Section 32.1 Summary – pages 841 - 847 Most mammals have specialized teeth • A lion’s canines puncture and tear the flesh of its prey.

24. Section 32.1 Summary – pages 841 - 847 Most mammals have specialized teeth • Premolars and molars are used for slicing or shearing, crushing, and grinding.

25. Section 32.1 Summary – pages 841 - 847 Most mammals have specialized teeth • Many hoofed mammals have an adaptation called cud chewing that enables the cellulose in plant cell walls to be broken down into nutrients they can absorb and use. • When plant material is swallowed, it moves into the first two of four pouches in the stomach where cellulose in the cell walls is broken down by bacteria.

26. Section 32.1 Summary – pages 841 - 847 Most mammals have specialized teeth • The partially digested food, called cud, is repeatedly brought back up into the mouth.

27. Section 32.1 Summary – pages 841 - 847 Most mammals have specialized teeth • After more chewing, the cud is swallowed again and when the food particles are small enough they are passed to the other stomach areas, where digestion continues.